Oh I shouldn't think they will spend any explicit time on that.
[In reply to]

Can't Post

And I can't find that this represents anything in the region of "serious" on my own spectrum.

I doubt that the motivation for the form of contract will be raised, nor the options (of which legalism is only one) be discussed. Similarly the question of the dwarves' natural approach to contracting is really, in my view, neither here nor there. The primary character interest is really in relation to Bilbo and in the slightly self-aggrandising style of the dwarves' ultimate product (which is maintained happily in the film version).

I also have to say I don't read the same things into Thorin's post song incredulity. He is exasperated that Bilbo has not already obtained the info that he needs and as a result tells the lengthy tale. The contract doesn't enter into Thorin's response at this point.

But to rerturn to the original thought, on reflection, I remain impressed at the genuinely funny, and very appropriate piece of work here.